Conventionally, there have been known fixing structures for a surface skin such as that disclosed in Patent Literature 1 (Japanese Unexamined Patent Application Publication No. 2005-306129). This fixing structure for a surface skin is applied to seat backs as vehicle seats. Specifically, a trim plate is fixed to a seat back frame, and a pad is mounted on the seat back frame. A plastic hook is attached to the edge part of an opening (i.e., hole) in a pouch-form surface skin, and the plastic hook is hooked onto the rim of an opening in the trim plate. Hooking the plastic hook fixes the surface skin to the trim plate (and, therefore, to the seat back frame).